Depth control of seal line penetration for rotary ultrasonic horn/anvil welding without mechanical stop

ABSTRACT

An apparatus for joining a first film portion and a second film portion together along a seal line. The apparatus includes a horn and anvil. The anvil is positioned close to the horn. The horn or anvil has a face that is rotatable about a rotation axis. The face has a raised profile, and a height thereof has a dimension corresponding to 50% to 150% of a thickness of the first film portion or the second film portion. The face is positioned such that the raised profile extends along the circumference such that continuous running contact is provided between the raised profile and the other of the one of the horn or the anvil when rotated about the rotation axis, to form the seal line without any external structure to control a distance between the horn/anvil. A tapered bonding profile, a traction pattern, and a cut-and-seal feature are also disclosed.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation-in-part of U.S. patent applicationSer. No. 17/399,429, titled “Depth Control of Seal Line Penetration ForRotary Ultrasonic Horn/Anvil Welding Without Mechanical Stop,” filedAug. 11, 2021, the entirety of which is incorporated herein by referencein its entirety.

FIELD OF THE INVENTION

The present disclosure relates generally to ultrasonic welding systems,and, more particularly, to depth control of seal line penetration for arotary ultrasonic horn or anvil welding without a mechanical stop.

BACKGROUND OF THE INVENTION

When bonding thin (thickness less than 150 μm) films, it can bedifficult to achieve consistent penetration with an air-loaded system.This is particularly true of monolayer and mono-material films. In someultrasonic welding applications, it is advantageous to use a horn andanvil that are disc-shaped, which are referred to as rotary horns orrotary anvils. When the application calls for a seal or joint to beformed between two substrates or layers to be joined of an end product(e.g., a pouch or container), some conventional rotary ultrasonictechniques employ a mechanical stop to control the depth of the joint orseal by stopping the advancing ultrasonic horn, but mechanical stopshave very severe limitations for thin film processing. A mechanical stoprequires near perfect and total concentricity of the rotating elements(rotary horn and rotary anvil), especially for thin film applicationsaround 0.002 inches (50 μm) in thickness, and is subject to mechanicalwear and tear over time, which adversely impacts consistent depthcontrol of the joint or seal. Mechanical stops also require the designerto eliminate the effects of thermal expansion and contraction, and theoperator would require a high level of accumulated skill to be able tomake micro adjustments to such a mechanical stop to accommodatedifferent film thicknesses. Mechanical stops are composed of multiplecomponents, such as bearings, shaft, and other components whosemanufacturing tolerances can induce small but significant elements ofrotational runout. If such runout were to occur, and due to the verysmall gap dimension required between the rotating elements, bondconsistency from end product to end product would be lost.

Other conventional rotary applications employing ultrasonic energy havea pattern of ridges formed on the surface of the rotary horn and/orrotary anvil, such as disclosed in U.S. Pat. No. 10,889,066 owned by thesame assignee of the present disclosure, which is particularly wellsuited for bonding nonwoven fabrics, by entrapping elastic strands in apermanent state of tension. These are not particularly well suited formelting plastics together to create a hermetic or airtight seal betweenthe two plastic parts. Moreover, the ridge pattern tends to have aheight far greater than a thickness of the fabric being bonded togetherby the ultrasonic energy. Patterned profiles also do not create hermeticseals, which are required in some applications, e.g., pouches orcontainers that will be filled with a liquid.

Still further conventional rotary ultrasonic welding applicationsincorporate a raised profile on the horn or anvil, but like patternedprofiles, the overall height of these raised profiles are greater(typically many orders of magnitude greater) than a thickness of theparts being joined together, and thus cannot serve to control the depthof the seal line and are not well suited for sealing thin filmstogether. Tall raised profiles like these lead to weakening of the bondor seal due to the high force/pressure applied, and are thus notdesirable for use in sealing (plastic) films.

FIG. 1A is a cross-section of a cutaway portion of a prior art anvil 100having a raised, patterned profile 102. The patterned profile 102 has aheight, H1, that is orders of magnitude greater than a thickness of alayer of a part sandwiched between the anvil 100 and a conventional hornthat receives ultrasonic energy. Due to the magnitude of height, H1, ahigh amount of force or pressure is applied to the layers sandwichedbetween the horn and anvil 100, which, particularly in the case wherethe layers are films, such as plastic films, can lead to an undesirableweakening (e.g., excessive thinning) of the seal line or bond formed atthe interface between the patterned profile 102 and the horn when themechanical stop insufficiently limits the weld force and distance due tolack of concentricity, thermal expansion, or improper operatoradjustment.

FIG. 1B is a cross-section of a cutaway portion of another prior artanvil 110, also having a raised profile 112, but the raised profile 112has a smooth surface as opposed to a patterned surface such as shown inFIG. 1A. Like the anvil 100, the raised profile 112 of the anvil 110shown in FIG. 1B has a height, H2 of 0.063 inches, much greater than athickness (typically more than double) of a layer of a part sandwichedbetween the anvil 112 and a conventional horn. Like the conventionalprofile shown in FIG. 1A, the conventional profile of FIG. 1B willoperate to weakening the bond or seal formed between film layers. Theraised profile 112 shown in FIG. 1B forms a continuous seal, but it canadversely thin the material being welded too much, thus weakening it andthe package being sealed when the mechanical stop insufficiently limitsthe weld force and distance due to lack of concentricity, thermalexpansion, or improper operator adjustment.

A need exists, therefore, for a rotary ultrasonic welding technique thatdoes not use a mechanical stop and can accurately and repeatedly jointwo thin parts (e.g., portions of film) together and accommodate partsof varying thickness. Aspects of the present disclosure are directed tofulfilling this and other needs.

SUMMARY OF THE INVENTION

Key features of the present invention are the height of the profile andthe absence of any mechanical stop device to control depth of the sealusing ultrasonic energy applied by a rotary horn and anvil. The heightof the profile is extremely small, such as between 50% and 150% or 100%of a thickness of the film or part being joined. The extremely lowheight of the profile on the horn or anvil (it can be present on either,or both), provides a “dynamic mechanical stop” effect without any actualexternal mechanical stop, by squeezing the two layers of film withenough force or pressure to achieve the mechanical support, but not sohard as to melt the plastic in the film layers. The combination of theheight of the profile and the absence of any mechanical stop structureto control depth of seal penetration is a key difference over the priorart.

The profile can extend continuously and circumscribe an entirecircumferential outer surface of a rotary horn or rotary anvil. Acontinuous, circumferential profile maintains a constant and continuousforce/pressure on the film while sealing while the profile's height isno greater than a thickness of the film.

The profile heights depend on a thickness of the film being sealed, butin some embodiments, the height of the profile can begin as low as0.002″ (inches) high and then step up very tiny, 0.0005″ increments,which demonstrates the high precision needed from an alternative designemploying a conventional mechanical stop as opposed to the depth controlanvil design of the present disclosure.

According to an aspect of the present disclosure, an apparatus forjoining a first film portion and a second film portion together along aseal line using ultrasonic energy is disclosed. The apparatus includes:a horn configured to receive ultrasonic energy; and an anvilpositionable in close proximity to the horn that is advanced toward theanvil, wherein at least one of the horn or the anvil has a face with awidth dimension and a circumference and is rotatable about a rotationaxis. The face has a raised profile, a height of the raised profile hasa dimension corresponding to 50% to 150% of a thickness of the firstfilm portion or the second film portion. The face is positioned suchthat the raised profile extends along the circumference. Continuousrunning contact is provided between the raised profile and the other ofthe one of the horn or the anvil when rotated about the rotation axis,to form the seal line without any external structure to control adistance between the horn and the anvil. The thickness of the first filmportion and the second film portion can be between 10 μm and 150 μm.

The height dimension of the raised profile can correspond to 100% of thethickness of the first film portion or the second film portion. Theheight dimension of the raised profile can correspond to between 50% and125% of the thickness of the first film portion of the second filmportion. The first film portion and/or the second film portion can becomposed of a plastic. The first film portion or the second film portioncan be a multilayer film, a recyclable film, a biodegradable film, acompostable film, a monolayer film, a paper-based film, or amono-material film.

The raised profile can further include a scoring element configured toscore or cut along the seal line as the anvil is rotated about therotation axis. The face can have a second raised profile having a heightcorresponding to 50% to 150% of the thickness of the first film portionor the second film portion. The second raised profile can extend alongthe circumference, and continuous running contact can be providedbetween the second raised profile and the other of the one of the hornor the anvil when rotated about the rotation axis.

The height dimension of the second raised profile can correspond to 100%of the thickness of the first film portion or the second film portion.The raised profile can be part of the anvil, and further in combinationwith a second anvil can have a second raised profile having a heightdimension exceeding the height dimension of the raised profile by 0.0005inches.

A product is disclosed which includes the first film portion and thesecond film portion and the seal line formed by any apparatus disclosedherein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a cross-section of a cutaway portion of a prior art anvilhaving a raised, patterned profile;

FIG. 1B is cross-section of a cutaway portion of another prior art anvil110, having a smooth, raised profile 112;

FIG. 2 is a perspective illustration of a rotary ultrasonic bondingapparatus suitable for use with the raised profile on either the anvilor horn, creating a dynamic stop effect;

FIG. 3 is an enlarged, cross-sectional view of a portion of a horn oranvil having a raised profile according to an aspect of the presentdisclosure;

FIG. 4 is an isometric, cutaway view of a horn or anvil according toanother aspect of the present disclosure having two raised profilesthereon, creating a dynamic stop effect thereby;

FIG. 5 is an isometric, cutaway view of the horn or anvil having tworaised profiles shown in FIG. 4 ;

FIG. 6 is a cross-sectional view of a portion of the horn or anvil shownin FIG. 5 ;

FIG. 7 is a cross-sectional view of a portion of the horn and the anviltogether with the raised profile with two layers of film passing betweenthe horn and anvil during application of ultrasonic energy;

FIG. 8 is a functional diagram of a depth control configuration in whicha horn and anvil each have a raised profile to achieve equal ordeliberately non-equal penetration from both sides of film being bonded;

FIG. 9A is a functional diagram of a seal and score configuration inwhich the raised profile includes a scoring element to score the sealedlayers after they have bonded;

FIG. 9B is a functional diagram of an angled seal profile configurationin which the raised profile is angled to facilitating in sealing thelayers to be bonded;

FIG. 10A is a cross-sectional view taken along line 10B-10B of a portionof the horn or anvil having a tapered bonding profile and an exemplarytraction pattern;

FIG. 10B is a top cut-away view of a portion of the exemplary tractionpattern shown in FIG. 10A;

FIG. 10C is a cross-sectional view of the portion of the tractionpattern taken along line 10C-10C;

FIG. 11A is a side view of a horn or anvil having a cut and sealfeature;

FIG. 11B is an enlarged view of the cut and seal feature shown in FIG.11A with a callout showing an enlarged view of the cutting feature; and

FIG. 12 illustrates a tapered bond profile on a horn or anvil, which canhave a different profile on either side of horn or anvil.

DETAILED DESCRIPTION

FIG. 2 is a general illustration of a rotary ultrasonic bondingapparatus 200, the general operation and components of which will bevery familiar to a person of ordinary skill in the art of ultrasonicwelding, and in particular, rotary ultrasonic welding technology. Theapparatus 200 has an anvil module 202 and a horn module 204, whichcooperate to perform a bonding or sealing operation of multiple parts,e.g., two or more layers of film, as set forth in more detail below.

The horn module 204 includes a frame 206 on which are mounted adisc-like rotary horn 208, a motor 210 for driving rotation of the horn208 via a suitable drive train 212, and a housing 214 that contains atleast part of a vibration control unit (not shown) that causes the horn208 to vibrate. The horn 208 has an exposed outer face 216 with asubstantially continuous contour (i.e., the horn face 216 has a contourthat is substantially smooth (or uninterrupted) across its entiresurface area). In other embodiments, the horn face 216 may have anysuitable contour that facilitates enabling the horn 208 to function asdescribed herein.

In some embodiments, the vibration control unit (while not illustrated)includes a conventional booster (e.g., a drive booster and an integralbooster) mechanically connected to a converter, which is electricallyconnectable to a generator. The converter is capable of converting highfrequency electrical energy supplied by the generator into mechanicalenergy (or vibration) that is selectively transmitted to the horn 208across the booster(s). The booster(s) are capable of modifying (i.e.,increasing or decreasing) the vibration transmitted to the horn 208 fromthe converter, such that the horn 208 (particularly, the face 216 of thehorn 208) vibrates while it rotates during a bonding operation, as setforth in more detail below. It is contemplated that the horn module 204may have any suitable operational components arranged in any suitablemanner that facilitates enabling the horn 208 to function as describedherein. The details not shown would be readily apparent to any personskilled in the art familiar with rotary ultrasonic bonding systems.

In the illustrated embodiments, the anvil module 202 includes a frame218 on which are mounted a disc-like rotary anvil 220 and a motor 222for driving rotation of the anvil 220 via a suitable drive train. Theanvil 220 has an exposed outer face 226 with a substantially continuouscontour (i.e., the anvil face 226 has a contour that is substantiallysmooth or uninterrupted across its entire surface area). The anvilmodule 202 is positioned relative to the horn module 204 such that theanvil face 226 is rotatable about a rotation axis, R (seen in FIG. 4 ),in close proximity to the horn face 216, and vice versa, to facilitateultrasonically bonding the parts as they are held in tension acrossapparatus 200, as set forth in more detail below. As used herein, theterm “close proximity” refers to when the anvil face 226 is either incontact with, or is minimally spaced apart from, the horn face 216 whenthe horn 208 is not ultrasonically vibrating.

In some embodiments, the apparatus 200 may be configured such that atleast one of the anvil module 202 and the horn module 204 isdisplaceable relative to the other via a suitable displacement mechanismoperable either: (A) when the system 100 is offline and the horn 208 isat rest (i.e., when the horn 208 is not rotating or vibrating); or (B)when the system 100 is online and the horn 208 is active (i.e., when thehorn 208 is rotating and vibrating).

With particular reference to the embodiment illustrated in FIG. 2 , theapparatus 200 may be configured as a continuous-nip apparatus in whichthe horn module 204 is to be: (A) fixed in position relative to theanvil module 202 when the system 100 is online and the horn 208 isactive; and (B) displaceable relative to the anvil module 202 when thesystem 100 is offline and the horn 208 is at rest. Such displacement isfacilitated by a selectively actuatable pneumatic cylinder 228 (or othersuitable linear actuator) that connects the frames 206, 218 to oneanother. In this manner, the spacing between the horn face 216 and theanvil face 226 is adjustable primarily for servicing the apparatus 200when the system 100 is offline.

FIG. 3 illustrates a cross section of a part of the horn or anvil 208,220 having an outer face 302 having a substantially continuous contour(i.e., the outer face 302 has a contour that is substantially smooth oruninterrupted across its entire surface area), and a raised profile 312having a height, H3, that is between 50% and 150% (e.g., 100%) of athickness of a part to be joined between the horn and anvil 208, 220. Itshould be emphasized that the raised profile 312 can be present on thehorn 208 or the anvil 220 or both, and the principles discussed hereinapply equally to both the horn 208 and the anvil 220. In mostapplications, the raised profile 312 is present on the anvil 220. Therecan be more than one raised profile 312, e.g., such as best seen in FIG.4 . Multiple raised profiles like the raised profile 312 can be presenton the horn 208, on the anvil 220, or distributed among the horn 208 andthe anvil 220 (e.g., a raised profile can be present on the horn 208,and a raised profile can be present on the anvil 220) for joining onepair of parts together or multiple pairs of parts together. The raisedprofile 312 can be referred to herein as a “depth control” profile,because it serves to control the depth of weld penetration into parts tobe joined together by sealing or bonding.

The raised profile 312 shown in FIG. 3 has a substantially flat andcontinuous raised surface having a width of 0.040 inches, and which istransitioned on both sides by a curved surface having a radius, R=0.015inches. The width of the raised profile 312 is also much narrowercompared to prior art non-patterned profiles, and e.g., spans less than10% or less than 7% or less than 5% of the entire width of the horn 208or the anvil 220. The radius dimension is exemplary, but plays a role inimparting a dynamic stop functionality to the rotary system without theneed for a mechanical stop found in prior art rotary ultrasonic weldingsystems. The radius dimension is also a function of the height, H3, ofthe raised profile 312, but the height, H3, is constrained not to exceeda thickness of a part, such as a film, to be joined between the horn 208and the anvil 220 by application of ultrasonic energy to the horn 208 asthe horn 208 and anvil 220 rotate relative to one another about arotation axis, R (seen in FIG. 4 ). In this example, the raised profile312 has a height, H3, e.g., that is about 0.0035 inches (within atypical tolerance). However, the height, H3, can be as low as 0.002inches to accommodate films of that thickness.

The horn 208 or the anvil 220 can be readily swapped out for anotherhorn 208 or anvil 220 having a differently sized (e.g., height and/orwidth) raised profile. The height, H3, of each raised profile can bemachined to differ by increments of only 0.0005 inches from profile toprofile. For example, if the smallest height profile has a height of0.0020 inches, the next profile can have a height of 0.0025 inches,followed by 0.0030 inches, and so forth. Using the example shown in FIG.3 , the raised profile 312 on one anvil 220 can have a height ofapproximately 0.003 inches, and another anvil can have a raised profilewith a height of 0.0035 inches, followed by 0.0040 inches, and so forth.Depending on the thickness of the parts (e.g., films) being joinedtogether, the anvil 220 or the horn 208 can be easily swapped out tomatch the raised profile's height with the part's thickness. It shouldbe emphasized that the dimensions or tolerances provided herein areexemplary only and are used to illustrate the relative height of theprofile relative to the thickness of the part layer(s) being welded orjoined together.

The raised profile 312 can encircle the entire circumference of the horn208 or the anvil 220, such as shown in the partial cutaway perspectiveview shown in FIG. 4 and in more detail in FIGS. 5 and 6 . Due to theextremely narrow height of the raised profiles 312 a, 312 b, FIGS. 5 and6 illustrate enlarged views of the raised profiles 312 a, 312 b (two areshown in FIG. 5 ). Energy for adequate bonding to occur at the profile312 is provided. It should be noted that the height of the raisedprofiles 312 a, 312 b can be different. This can be useful, e.g., whenthe raised profiles 312 a, 312 b are on the horn 208, and the anvil 220has a narrower width compared to the horn 208. This allows the operatoror end user to use the same horn 208 for welding different partthicknesses by simply flipping the horn 208 around so that theappropriate raised profile (312 a or 312 b) is in contact with the anvil220. For example, if the raised profile 312 a has height X, and theraised profile 312 b has height Y>X, when the thicker part is needed tobe welded, the horn 208 can be flipped so that the raised profile 312 bcontacts the anvil 208; whereas when a thinner part is needed to bewelded, the horn 208 can be flipped so that the raised profile 312 acontacts the anvil 208 instead. It should be emphasized that therespective widths of the horn 208 and the anvil 220 can be the same ordifferent (e.g., the anvil 208 can be thinner or narrower compared tothe horn 220 when the raised profiles 312 a, 312 b are present on thehorn 220).

FIG. 7 illustrates an example cross-section of two parts, which in thisexample are two layers of film comprising a lower film 400 and an upperfilm 402. As the layers 400, 402 are pulled between the horn 208 and theanvil 220, the layers 400, 402 begin to melt due to the application ofultrasonic energy into the horn 208. The layers 400, 402 are squeezed bythe raised profile 312 as they move or are moved along a direction ofarrow G shown in FIG. 7 into a space by force or pressure, which has aheight corresponding to a thickness of only one of the layers 400, 402(because the height of the raised profile 312 does not exceed thethickness of one of the layers 400, 402). It is assumed that thethickness of the layers 400, 402 are the same, but they do not have tobe identical. The height, H3, of the raised profile can be dimensionedto accommodate the thicker of the two layers 400, 402.

An important aspect of the dimension of the height of the raised profile312 is that it creates a dynamic stop effect without the need for anexternal mechanical stop apparatus. When the layers 400, 402 enter thegap between the horn 208 and the anvil 220, the amplitude of theultrasonic energy and the nip force created at the raised profile 312provide sufficient energy for bonding to occur along the raised profile312. There is insufficient energy to bond in areas between the horn 208and anvil 220 beyond the raised profile due to the weld force's beingdistributed across increased surface area after profile penetration hasbeen achieved. In these areas, the unbonded layers 400, 402 preventcontact between the horn 208 and the anvil 220. As a result, thiseliminates the need for an external physical mechanical stop, whichotherwise would be required to maintain seal line thickness andconsistency. The unbonded layers between the horn 208 and the anvil 220become the physical stop conventionally provided by a mechanical stop,but which is eliminated by the aspects of the present disclosure herein.

In prior art systems, when the raised profile has a height much greaterthan the thickness of the film being presented between the horn andanvil, an external mechanical stop device is required to inform thesystem when to stop advancing movement of the horn. Otherwise, anexcessive or inadequate amount of force or pressure can be applied tothe films, and an inadequate or inferior bond formed at the sealinginterface. By contrast, a depth control profile such as the profile 312has a much shallower profile and is also narrower. This continuousprofile (see FIG. 4 ) can weld the film 400, 402 by initiating the melton the profile surface 312 until the profile 312 penetrates to the depthof the adjacent shoulders. Once the shoulder meets the film 400, 402,the much larger surface area bottoms out on the shoulders and the meltsand penetration are halted (referred to herein as a dynamic stopeffect).

The gap between the horn 208 and anvil 220 and resultant seal linethickness is determined by profile height as a percentage of thethickness of a single material ply. E.g., if material thickness=x, thenthe profile height is a predetermined percentage of x, typically 50% to150%, depending upon the material being bonded and desired bondingresult (e.g., hermetic seal).

The benefit of welds made by the apparatus and methods according to thepresent disclosure over prior art rotary systems is that the continuousweld is stronger and forms a hermetic seal. The raised profile accordingto the aspects of the present disclosure can be applied to multilayer,recyclable, biodegradable, compostable, monolayer, paper-based, ormono-material films. Full control of the seal line thickness isachievable according to aspects of the present disclosure, for materialthicknesses in a range from 10 μm up to 150 μm.

As mentioned above, a raised profile can be present on both the horn 208and the anvil 220, with the same or unequal heights. FIG. 8 illustratesan example depth control configuration 800 in which one of the horn 208or anvil 220 has a first raised profile 812 a, and the other of theanvil 220 or horn 208 has a second raised profile 812 b, both of whichhave been exaggerated grossly as shown in size and profile for ease ofillustration and discussion. A product 802, such as a pouch or containerto be filled with a liquid, and thereby requiring a hermetic seal, has afirst layer 400 and a second layer 402. Each raised profile 812 a, 812 bmust have a height of less than 100% of x (where x is the thickness ofthe layer 400, 402) when the profiles have the same height. When theprofiles have different heights or where unequal penetration isrequired, one element may exceed 100% of x, but the other must beproportionately less. While both the horn 208 and the anvil 220 areshown in FIG. 8 as having a raised profile 812 a, 812 b, in alternateembodiments, only one of the horn 208 or the anvil 220 can have a raisedprofile while the other of the horn 208 and the anvil 220 lacks a raisedprofile.

For example, if thickness of the layer 400, 402 is 100 um (x=100) and aseal thickness at an interface 830 of 25 μm is desired, and the seal 830needs to be offset, a profile height of 125% of x on one element 812 a(horn 208 or anvil 220) and a profile of 50% x on the second element 812b (anvil or horn) will achieve an offset seal line of 25 um thickness.If equal penetration is required, then both horn 208 and anvil 220 wouldhave a raised profile 812 a, 812 b having a height corresponding to87.5% of x. The unbonded layers 400, 402 in an area 832 downstream ofthe seal interface 830 prevent contact between the horn 208 and theanvil 220. As a result, the need for an external physical mechanicalstop is eliminated, which otherwise would be required to maintain sealline thickness and consistency. The unbonded layers 400, 402 in the area832 between the horn 208 and the anvil 220 become the physical stop.

FIG. 9A illustrates a “seal and score” configuration 900 in which theraised profile 912 on either the horn 208 or the anvil 220 includes ascoring element 916 to score or cut the sealed interface 930 of thebonded layers 400, 402 right at one of the distal (relative to theproduct 902) shoulders of the raised profile 912. The unbonded layers400, 402 in the area 932 are scored or cut from the sealed interface930, enabling a sealing and scoring operation to take place in one step.Again, like the configuration 800 shown in FIG. 8 , the raised profile912 and scoring element 916 shown in FIG. 9A has been grosslyexaggerated for ease of illustration and discussion. The scoring element916 can have a wedge shape to score other materials, such as in shrinkwrap applications. The unbonded film in the area 932 maintains the bondand score depth, eliminating the possibility of the horn 208 beingdamaged by the anvil 220 (assuming the scoring element 916 is part ofthe raised profile 912 of the anvil 220).

FIG. 9B illustrates an “angled seal profile” configuration 950 in whichthe raised profile 952 on either the horn 208 or the anvil 220 includesan angled profile to aid in sealing or bonding the sealed interface 930of the bonded layers 400, 402. The product package or container 902(e.g., containing contents 960 such as liquids, powders, gels, food, orthe like, within the sealed enclosure) has the sealed interface 930created in part by the angled profile of the raised profile 952. Asshown in FIG. 9B, the seal line of the raised profile 952 is angledacross the interface 930 with its shallow edge adjacent or closest tothe product 902. The angle increases or tapers away from the product 902as the distance from the product 902 increases along the interface 930.The angled profile of the raised profile 952 improves speed andincreases seal strength while diverting more melt material 400, 402toward the product side.

Additional features that can be incorporated with any of the raisedprofiles disclosed herein will be discussed in connection with FIGS. 10Athrough 11B. Three features broadly summarized as “traction,” “taperedbond profile” and “cut and seal” will be described next. Some of thefeatures can be combined, such as the traction feature can be combinedwith the tapered bond profile feature, such as shown in FIG. 10A.

FIG. 10A illustrates a horn or anvil 208, 220 such as disclosed aboveincorporated in a rotary ultrasonic bonding apparatus 1000, which hasthe same basic structure as the rotary ultrasonic bonding apparatus 200disclosed above, except that a traction feature 1020 is shown downstreamof the raised profile 1012, and a tapered bond profile feature 1014 isshown upstream from and leading to the raised profile 1012.

Example dimensions of the features shown in FIG. 10A are summarized inthe table below.

Inches/ Milli- Dimension Degrees meters W1 (width of raised bond profile1012) 0.049- 1.2-13 0.051 W2 (width of raised bond profile 1012including 0.103 2.6 tapered bond profiles 1014, 1016) W3 (gap betweentrailing tapered profile 1016 and 0.015 0.4 traction feature 1020) W4(distance between edge of horn/anvil 208, 220 0.080 2.0 and start ofleading tapered profile 1014) W5 (offset from center of raised bondprofile 1012 0.025 0.6 and radius of trailing tapered profile 1016) α1(angle of leading tapered bond profile 1014 1.15° relative to top flatsurface of raised bond profile 1012) R1 (radius of taper of the trailingtapered bond profile 0.098 2.5 1014) H4 (height of raised bond profile1012)  0.0035 0.1 H5 (maximum height of the traction feature 1020) 0.0050.1

In the example raised bond profile 1012 shown in FIG. 10A, the height,H4, of the raised bond profile relative to the surface of the horn/anvil208, 220 is 0.0035 inches or about 0.1 mm. Leading to the raised bondprofile 1012 is a leading tapered bond profile 1014 having a taper ofangle α1 across the face of the horn/anvil 108, 220. The angle α1 can bebetween 0.5 and 5 degrees, and in this example, is shown to have anangle of about 1.15 degrees. Following the raised bond profile 1012 is atrailing tapered bond profile 1016 followed by the traction or patternfeature 1020.

The traction feature 1020 offers a feature to pull the material throughand past the ultrasonic nip and so the ultrasonic nip needs to provideits own drive. Vertical Form Fill & Seal packaging systems (FFS) areparticularly well-suited for the traction feature 1020, because thesesystems lack a way of pulling the material. An example pattern 1020 canbe seen in FIG. 10B, in which an array or pattern of raised nubs orprotrusions 1004 are distributed in a grid-like pattern on the surfaceof the horn/anvil 208, 220. The pattern 1020 is designed to avoidexcessive, localized heat build-up, particularly in the presence ofmonolayer films, so the pattern 1020 should not detract from therequired drive of the material through the FFS system. The pattern 1020is exemplary only, and while it has been shown in a pattern that runsparallel with the edges of the horn or anvil 208, 220, the pattern 1020can be pitched at an angle relative to the edges, such as between 1 and15 degrees, to provide a desired drive characteristic without creatingexcessive heat build-up. Likewise, the shape and form of the nubs orprotrusions 1004 can be modified from that shown to provide a pulling orgrabbing friction to the passing material. For example, the nubs 1004can have a tooth-like shape. In the example shown in FIG. 10C (takenalong line 10C-10C shown in FIG. 10B), the nubs 1004 can be seen to havea tapered profile as shown with an angle α2 Example values of thedimensions shown in FIG. 10B appear in the table below.

Dimension Inches/Degrees Millimeters W6 (gap between adjacent nubs 1004)0.016 0.4 W7 (width of nub 1004) 0.014 0.3 H6  0.0030 0.1 H7 0.005 0.1α2 30-50°

Horizontal applications can also benefit from the traction feature 1020.For example, in applications where a zipper is to be included, there ismaterial that is pre-heated just before the bond, and there is slacknessalong the edge caused by laser-scoring of the film. The pre-heating andedge slackness caused by the laser scoring creates control problems,namely the material was difficult to keep in the nip of the horn/anvil208, 220. The traction pattern 1020 avoids these problems.

Returning to FIG. 10A, a tapered bond profile or feature 1014 can beseen on the leading side of the raised bond profile 1012. The taper,shown by angle α1, can range from 0.5 to 5 degrees, and in theillustrated example, the angle is 1.15 degrees. The product side of thebond would be to the left of FIG. 10A (e.g., in the case of a zipperedpillow pack, the zipper would be to the right of FIG. 10A, and theproduct or contents inside the pillow pack would be to the left of thetapered bond profile 1014.

The tapered bond profile 1014 provides several advantages. First, meltflow is directed towards the product side, which provides an improvedseal. A flat profile (e.g., FIG. 3 ) could displace material equally butin an uncontrolled way on both sides of the bond, whereas a tapered bondprofile 1014 would direct the melt in a more controlled way towards theproduct, resulting in a thicker stronger seal on this side of the bond.Additionally, the tapered design is resilient to material thicknessvariation, e.g., some materials have up to a 40% variation in materialthickness). Put another way, if the maximum combined thickness (2layers) were 180 μm, but could be as little as 108 μm, a depth controlanvil with a 88 μm profile would over-penetrate at its highest point;however, the lateral taper 1014 would mean that the ideal bonding pointwould shift from the highest point of the horn/anvil 208, 220 acrosstowards the lowest point ensuring that even with a material thicknessvariation, ideal bonding conditions will still be satisfied at somepoint across the profile of the horn/anvil 208, 220. The tapered design1014 also allows a broader range of film thicknesses to be used on thesame anvil or horn 208, 220.

It should be noted that the tapered bond profile would not work on ananvil/horn that does not use depth control because over-penetrationwould quickly occur, and the anvil would become a cutting tool ratherthan a bonding tool. The tapered bond profile 1014 disclosed hereinworks with the depth control profile 312, 1012, such as shown in FIGS.3, 10A-10C, but would not be suitable on a conventional anvil that doesnot have a raised depth control profile 312, 1012 such as disclosedherein. The tapered profile design also provides a speed improvement asit more easily penetrates the material during the bond process.

In general, thinner materials require a shallower angle of the taper inthe tapered bond profile 1014. Higher speeds can be achieved as well asimproved sealing compared to non-tapered raised profiles. The taper ofthe tapered bond profile 1014 can be defined by a radius (e.g., a curve)or an angle (e.g., a ramp or α1 shown in FIG. 10A).

With certain packaging films, conventional radiused (non-depth control)profiles can be problematic as they produce a “porpoising effect.” Thisis caused when the radiused anvil starts to penetrate the material butas depth of penetration increases, surface contact between the anvilprofile and the material being bonded increases exponentially, whichresults in a situation where amplitude and pressure are insufficient tomaintain the depth of anvil penetration, this forces the anvil toretract against the pressure exerted by the material. As it does so, thecontact area then decreases exponentially resulting in an excess ofpressure and amplitude for the reduced depth of bond, and so the anvilpenetration increases, causing the cyclic “porpoise” effect.

By contrast, use of an angled profile 1014 (such as α1 shown in FIG.10A) is not as sensitive to these effects, because the angle of attackof the tapered bond profile 1014, married to profile bond height (H4) ofthe flat raised profile 1012, is determined based on a range of filmthicknesses.

Additional advantages of the tapered bond profile 1014 include:

Improved speed due to easier material penetration

Improved sealing—an angled profile 1014 having the shallow side towardsthe product helps improve seal strength by controlling the melt flow anddirecting it to the product side of the seal. This also improves vacuumtank testing performance and reduces the possibility of a fault linebeing created in the film by the bond process.

Reduced particulate spread—the shallow angle (α1) of the taper in thetapered profile 1014 traps and attaches particulates within the bondline, so no bond will occur at the shallow side of the seal line butfirm contact pressure will be applied, entrapping the particulates.

Simultaneous seal/cut possibility—Utilizing an angle (e.g., α1) allows areliable cut/seal on both depth control and non-depth controlapplications. Depth of cut can be accurately controlled by adjustingapplication pressure and/or amplitude. The system would leverageunbonded material under the shallow edge of the anvil profile 1012 toact as a compressible depth stop in relation to penetration of theopposite, knife-side (1130, FIG. 111B) of the angle. The bond occursbetween the knife point 1130 and the shallower edge of the profile(e.g., 1014 in FIG. 10A).

Next, the “cut and seal” feature will be described in connection withFIGS. 11A and 11B. In some applications, it is desirable tosimultaneously seal and cut or score shrink wrap or other material toprovide a zero fin seal height and a virtually invisible seal. FIGS.11A-11B illustrate a horn or anvil 208, 220, utilizing depth controlthat would penetrate the film material with a combined two-layerthickness of, e.g., 30 μm and leaving 4 μm uncut, which is then easilyparted by a conventional vacuum removal system (not shown), a step thatwill be readily familiar to those skilled in the art to which thepresent disclosure pertains.

Example dimensions are summarized in the table below.

Dimension Millimeters W8 2.55 W9 0.35 W10 2.0 H8 0.4 H9 0.026 R3 0.50

The angle of the profile (critical to achieve the desired result)ensured that the bonding conditions of force were met in a narrow arearesulting in a very narrow, but on this film at least, very strong bondthat withstood post bond shrink wrap activation. As can be seen in FIG.11A, the anvil/horn 208, 220 has two bond profiles, one on each edge,which can be used for applications where the sonotrode has a width lessthan a width of the anvil 208, 220. In the anvil or horn 208, 220 shownin FIG. 11A, the depth control profile 1112 is the entire center sectionbetween the two profiles. In FIG. 11B, an enlarged view of the cuttingsection is shown, where the cutting feature 1130 having a height, H9,provides a cutting feature to the film (e.g., shrink wrap) presented atits surface or interface. The cutting feature 1130 has a height, H9,that is slightly more raised compared to the height of the raisedprofile 1112. The cutting feature 1130 forms a generally sharp 90 degreeangle relative to the surface of the raised profile 1112, and thisabrupt transition provides the cutting action to the film or materialpassing by the anvil/horn 208, 220. The height, H9, of the cuttingfeature 1130 can be between 1% to 20% of the height, H4, of the raisedprofile 1012, 1112. The cutting feature 1030 forms a terminus of theraised profile 1112 and thus is positioned adjacent to or at an end ofthe raised profile 1112.

FIG. 12 illustrates a tapered bond profile having two different profileson either side of the horn/anvil 208, 220. Only one side of thehorn/anvil 208, 220 is shown here for ease of illustration due to therelatively small dimensions of the profile. Example values for thedimensions labeled in FIG. 12 are illustrated in the table below. Theprofile includes an angled profile 1214 having an angle α3, a depthcontrol profile 1212, followed by a trailing edge profile 1016, whichcan be angled or sloped.

Dimension Degrees Millimeters W11 2.6-2.7 W12 1.25 H10 0.0635- 0.089 H110.0635- 0.089 α3 1.5°, 1.8°, 2°

According to other aspects of the present disclosure, enhanced depthcontrol (and anvil geometry details) can be coupled with generatoroutputs. For example, adding a specific depth control and anvil detailresults in higher ultrasonic power (and thus allows for better seal andfaster speed). Limits and power regulation can be set around theseparameters.

The present disclosure produces a more consistent power draw, astability not seen with a non-depth control, radiused anvil. In fact, alower power draw using the angled profile 1014 is achieved compared to aradiused anvil, which leads to higher speed capabilities.

What is claimed is:
 1. An apparatus for joining a first film portion anda second film portion together along a seal line using ultrasonicenergy, the apparatus comprising: a horn configured to receiveultrasonic energy; and an anvil positionable in close proximity to thehorn that is advanced toward the anvil, wherein at least one of the hornor the anvil has a face with a width dimension and a circumference andis rotatable about a rotation axis, the face having a raised profilerelative to the face, the raised profile having a tapered side, thetapered side having a radius between 0.5 and 5 degrees relative to atopmost surface of the raised profile, the face being positioned suchthat the raised profile extends along the circumference, and continuousrunning contact is provided between the raised profile and the other ofthe one of the horn or the anvil when rotated about the rotation axis,to form the seal line without any external structure to control adistance between the horn and the anvil.
 2. The apparatus of claim 1,wherein the thickness of the first film portion and the second filmportion is between 10 μm and 150 μm.
 3. The apparatus of claim 1,wherein a height dimension of the raised profile relative to the facecorresponds to 50% to 150% of the thickness of the first film portion orthe second film portion.
 4. The apparatus of claim 1, wherein the faceincludes a traction feature having a height dimension that does notexceed a height of the raised profile, the traction feature including aplurality of protrusions arranged in a grid or pattern, the tractionfeature being adjacent to the raised profile.
 5. The apparatus of claim4, wherein the plurality of protrusions are arranged in rows or columnsthat are non-parallel with edges of the face.
 6. The apparatus of claim1, wherein the face includes a cutting feature having a higher heightcompared to a height of the raised profile, the height of the raisedprofile corresponding to 50% to 150% of the thickness of the first filmportion or the second film portion.
 7. The apparatus of claim 6, whereinthe height of the cutting feature is between 1% and 20% of the height ofthe raised profile.
 8. The apparatus of claim 1, wherein the raisedprofile including the tapered side is part of the anvil.
 9. Theapparatus of claim 6, wherein the cutting feature is adjacent to theraised profile and forms a terminus thereof.
 10. A product including thefirst film portion and the second film portion and the seal line formedby the apparatus of claim
 1. 11. The apparatus of claim 1, wherein thefirst film portion and the second film portion are composed of aplastic.
 12. The apparatus of claim 1, wherein the first film portion orthe second film portion is a multilayer film, a recyclable film, abiodegradable film, a compostable film, a monolayer film, a paper-basedfilm, or a mono-material film.
 13. The apparatus of claim 1, wherein aheight of the topmost surface of the raised profile relative to the faceis about 0.0035 inches.
 14. The apparatus of claim 1, wherein the radiusof the tapered side is 1.15 degrees relative to the topmost surface ofthe raised profile.
 15. The apparatus of claim 1, wherein the raisedprofile further includes a second tapered side, the second tapered sidehaving a radius between 0.5 and 5 degrees relative to the topmostsurface of the raised profile.
 16. An apparatus for joining a first filmportion and a second film portion together along a seal line usingultrasonic energy, the apparatus comprising: a horn configured toreceive ultrasonic energy; and an anvil positionable in close proximityto the horn that is advanced toward the anvil, wherein at least one ofthe horn or the anvil has a face with a width dimension and acircumference and is rotatable about a rotation axis, the face having araised profile relative to the face, the raised profile having a taperedside, the tapered side having a radius between 0.5 and 5 degreesrelative to a topmost surface of the raised profile, the face beingpositioned such that the raised profile extends along the circumference,and continuous running contact is provided between the raised profileand the other of the one of the horn or the anvil when rotated about therotation axis, to form the seal line without any external structure tocontrol a distance between the horn and the anvil, wherein the thicknessof the first film portion and the second film portion is between 10 μmand 150 μm.
 17. An apparatus for joining a first film portion and asecond film portion together along a seal line using ultrasonic energy,the apparatus comprising: a horn configured to receive ultrasonicenergy; and an anvil positionable in close proximity to the horn that isadvanced toward the anvil, wherein at least one of the horn or the anvilhas a face with a width dimension and a circumference and is rotatableabout a rotation axis, the face having a raised profile relative to theface, the raised profile having a tapered side, the tapered side havinga radius between 0.5 and 5 degrees relative to a topmost surface of theraised profile, the face being positioned such that the raised profileextends along the circumference, and continuous running contact isprovided between the raised profile and the other of the one of the hornor the anvil when rotated about the rotation axis, to form the seal linewithout any external structure to control a distance between the hornand the anvil, wherein the first film portion and the second filmportion are composed of a plastic.